1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS 8218 : 1998 ICS 91.060
2、.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Code of practice for Mastic asphalt roofingBS 8218 : 1998 This British Standard, having been prepared under the direction of the Sector Board for Building and Civil Engineering, was published under the authority of the Standa
3、rds Board and comes into effect on 15 January 1998 BSI 1998 The following BSI references relate to the work on this standard: Committee reference B/546/7 Draft for comment 95/105386 DC ISBN 0 580 28384 4 Amendments issued since publication Amd. No. Date Text affected Committees responsible for this
4、British Standard The preparation of this British Standard was entrusted by Technical Committee B/546, Flexible sheets for water and water vapour control, to Subcommittee B/546/7, Mastic asphalt for building purposes, upon which the following bodies were represented: Bitumen Modifiers Association Dep
5、artment of the Environment Department of the Environment (Building Research Establishment) Department of Transport Low Temperature Coal Distillers Association of Great Britain Ltd. Mastic Asphalt Producers Association Society of Chemical IndustryBS 8218 : 1998 BSI 1998 i Contents Page Committees res
6、ponsible Inside front cover Foreword ii Code of practice 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Exchange of information and time schedule 2 5 Materials 2 6 Design considerations 4 7 Site work 26 8 Workmanship 27 9 Protection 28 10 Inspection, sampling and testing 28 11 Maintenance and
7、repair 28 Annexes A (informative) Rigid thermal insulation boards 30 B (informative) Characteristics of mastic asphalt 31 Table 1 Treatments for vertical and sloping surfaces to receive mastic asphalt 19 Figures 1 Timber roof deck with free standing kerb (cold roof) 7 2 Timber roof deck with free st
8、anding kerb (warm roof) 8 3 Metal roof deck with free standing kerb (warm roof) 9 4 Concrete roof deck and skirting (cold roof) 9 5 Concrete roof deck and skirting (warm roof) 10 6 Concrete roof deck and skirting (inverted roof) with external insulant 11 7 Access decks, drying and playing areas (col
9、d roof) 13 8 Waterproofing to roof garden (partly insulated) 13 9 Waterproofing to roof garden (fully insulated) 14 10 Private balconies with tiles (bitumen bedded) 15 11 Private balconies and podia with tiles (cement mortar bedded) 15 12 Timber upstand expansion joint (cold roof) 17 13 Concrete ups
10、tand expansion joint (warm roof) 18 14 Timber valley gutter and brick parapet 21 15 Sleeved pipe passing through roof (warm roof) 22 16 Apron and drip to concrete (optional water check) 23 17 Apron and drip to timber (optional water check) 23 18 Timber roof eaves gutter (warm roof) 24 19 Concrete ro
11、of eaves gutter (warm roof) 25 20 Clamping cone type outlet 26 List of references 32ii BSI 1998 BS 8218 : 1998 Foreword This British Standard has been prepared by Subcommittee B/546/7. It supersedes CP 144 : Part 4 : 1970, which is withdrawn. This standard recognizes the increased use of thermal ins
12、ulation materials in warm roof and inverted roof concepts, indicating, where necessary, the essential detailing for such constructions. It also acknowledges current industry practices for the application of mastic asphalt in roofing. This British Standard gives guidance on mastic asphalt roofs desig
13、ned in accordance with BS 6229. A flat roof typically comprises ceiling, structural supports, roof deck, waterproof covering and surface protection, and incorporates insulation and drainage. It may support ancillary items such as engineering equipment, hand railing, and lightning conductors. Mastic
14、asphalt is a type of asphalt composed of suitably graded mineral matter and asphaltic cement in such proportions as to form a coherent, impermeable mass, solid or semi-solid under normal temperature conditions, but sufficiently fluid when brought to a suitable temperature to enable spreading by mean
15、s of a hand float, or by mechanical means. Mastic asphalt roofing requires the use of ancillary materials and products, most of which are covered by British Standards. Specifiers should satisfy themselves, by reference to manufacturers information and test results, that materials and products not co
16、vered by a British Standard will be suitable for their roofing requirements in particular situations and are compatible with the use of mastic asphalt. All such materials should be installed in accordance with manufacturers instructions. It has been assumed in drafting this standard that its applica
17、tion will be carried out by trained personnel under the direction of qualified supervisors. As a code of practice, this British Standard takes the form of guidance and recommendations. It should not be quoted as if it were a specification and particular care should be taken to ensure that claims of
18、compliance are not misleading. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 32, an inside back cover and a back cover. BSI 1998 1 BS 8218 : 1998
19、Code of practice 1 Scope This British Standard gives recommendations for the use of mastic asphalt in roofing for both flat and sloping roofs and covers a variety of applications, including trafficked roofs such as roof top car parks. 2 Normative references This British Standard incorporates, by dat
20、ed or undated reference, provisions from other publications. These normative references are made at the appropriate places in the text and the cited publications are listed on the inside back cover. For dated references, only the edition cited applies; any subsequent amendments to or revisions of th
21、e cited publication apply to this British Standard only when incorporated in the reference by amendment or revision. 3 Definitions For the purposes of this British Standard, the definitions given in BS 6100 : Subsection 1.3.2 apply, together with the following. 3.1 access roof Roof used to provide f
22、oot traffic access to plant or equipment which requires servicing, maintenance, repair or renewal. 3.2 terrace roof Flat roof for use as an amenity area. 3.3 roof top car park Flat roof designed for use as a car park. 3.4 cross fall; fall A slope created in the base for the purpose of shedding water
23、 to outlets or gutters. 3.5 substrate Surface upon which mastic asphalt roofing is laid. 3.6 roof deck Part of the roof construction which carries the load. 3.7 cold deck roof (cold roof) Roof in which any thermal insulation is beneath the roof deck. NOTE. In heated buildings it is essential that an
24、y void between deck and insulation is ventilated. 3.8 warm deck roof (warm roof) Roof in which the principal thermal insulation is placed above the roof deck, but below the waterproof covering. 3.9 inverted roof (upside down roof) Warm deck roof in which thermal insulation is placed above the waterp
25、roof covering. 3.10 thermal insulation Material laid to prevent heat loss from the building. 3.11 vapour control layer Layer of vapour resistant material applied specifically to control the passage of moisture vapour. 3.12 spreader Operative skilled in the laying and finish of mastic asphalt. 3.13 c
26、oat Single layer of mastic asphalt. 3.14 gauge Wood or metal strips of required thickness, temporarily fixed as boundaries to bays or elsewhere, to assist the spreader in laying the mastic asphalt. 3.15 float Flat-faced wooden tool, with a handle, used for spreading and finishing the surface of mast
27、ic asphalt. 3.16 rubbing Process by which the last coat of mastic asphalt is given a matt surface finish by the use of clean, coarse sand. 3.17 mechanical asphalt mixer A mobile container, fitted with heating and powered stirrers, to provide mechanical agitation, used for re-melting mastic asphalt.
28、3.18 mastic asphalt cauldron Steel vessel, non-mechanically agitated, fitted with a fire-box and used at the site of works for re-melting mastic asphalt prior to laying. 3.19 insulated dumper Dumper truck with insulated container and mechanical agitation for the transportation of molten, mastic asph
29、alt to point of laying. 3.20 hot charge transporter A specially adapted vehicle, fitted with a mechanical asphalt mixer for delivery of ready-to-use mastic asphalt to site. 3.21 bitumen boiler A vessel similar in construction to a mastic asphalt cauldron, used for the purpose of melting bitumen comp
30、ound.2 BSI 1998 BS 8218 : 1998 4 Exchange of information and time schedule 4.1 General Consultations and exchange of information between all parties concerned with the building operations should be arranged at an early date, so that each may have full knowledge of the particulars of the work and be
31、able to cooperate in producing the conditions required by the other to complete a satisfactory job. 4.2 Exchange of information The designer should provide in good time all relevant information to those responsible for laying the roofing and to others whose work may be affected, including whichever
32、of the following are applicable: a) description, situation and address of site and means of access; b) those conditions of contract which may practically affect this particular work; c) location levels and dimensions of the areas to be roofed; d) the construction, including the deck and any preparat
33、ions required; e) falls and drainage arrangements; f) any penetrations, fixtures or attachments; g) provision for access; h) nature of traffic and surface finish required; i) any vapour control layer; j) provision for temporary storage of materials and location of plant including limitations of roof
34、 loading; k) any special application (e.g. reservoir roof or roof top garden); l) date for the completion of preliminary work; m) dates for the start and completion of various sections of the roof; n) any conformance testing required; o) requirements relating to samples of mastic asphalt for testing
35、 purposes; p) requirements for supervision and inspection. 4.3 Provision of utilities, facilities and materials To prevent misunderstanding, particularly at the tendering stage, and to avoid possible situations detrimental to installation, it should be made clear whether or not the following will be
36、 provided and by whom: a) adequate, clean, dry lockable storage space protected from frost (if necessary); b) secure storage compound for gas bottles having a fence not less than 2 m high; c) adequate ventilation in confined areas; d) adequate artificial lighting if required; e) provision of a suita
37、ble level site for the mixer or mixers, blocks, and where relevant coarse aggregate, as close as is practical to the work; f) unloading and hoisting facilities if required; g) provision of scaffolding, hoists, ladders and safety equipment, temporary lighting, power, water and temporary protection; h
38、) adequate protection of the mastic asphalt against damage prior to and during laying and during the course of subsequent building operations; i) facilities for removal of rubbish and surplus material. 4.4 Time schedule In considering the schedule, in addition to the usual intervals between commence
39、ment and completion of work by the various trades involved, additional allowances should be made for the curing and drying of the base concrete or screed before the roofing is laid, where appropriate. 5 Materials 5.1 Mastic asphalt BS 6925 embraces asphalts for roofing, tanking and flooring; type R
40、988 specifically covers roofing grades. Asphalt paving is covered by BS 1447. NOTE. Polymer modified asphalts for roofing and paving are available manufactured by individual companies on a proprietorial basis. There is at present no British Standard for these asphalts. BSI 1998 3 BS 8218 : 1998 5.2
41、Coarse aggregate Coarse aggregate for paving grades should be crushed rock conforming to 5.3.1 of BS 1447 : 1988. 5.3 Separating membrane The separating membrane should be one of the following: a) sheathing felt comprising a base of flax or jute, or other suitable fibres, impregnated with bitumen; o
42、r b) a glass fibre tissue, mass per unit area 50 g/m 2 to 70 g/m 2 . 5.4 Isolating membrane The isolating membrane to be laid over mastic asphalt should be one of the following: a) a waterproof building paper or a single layer of roofing felt where cementitious materials are to be laid onto mastic a
43、sphalt; or b) a non-woven polyester fleece, mass per unit area 130 g/m 2 to 140 g/m 2 where extruded polystyrene is to be laid onto mastic asphalt in the inverted roof construction. 5.5 Vapour control layer The vapour control layer should be a single coat of mastic asphalt conforming to type R988 of
44、 BS 6925 or a roofing felt in accordance with BS 8217. 5.6 Thermal insulation 5.6.1 Rigid thermal insulation boards Rigid thermal insulation boards used on warm deck roofs and inverted roofs should be supplied and fixed by the roofing contractor. In a warm deck roof construction it is essential that
45、 the choice of thermal insulation, and its method of attachment, is considered in relation to any vapour control layer (see 6.6). 5.6.2 Insulating screeds Several cementitious screeds are available in the following categories: a) lightweight aggregate formed from expanded clay or sintered pulverized
46、 fuel ash, bonded with a cement binder; b) cellular aerated concrete. NOTE. Insulation materials suitable for use in flat roofs are given in BS 6229 (see also annex A). 5.7 Expanded metal lathing Bitumen coated plain expanded metal lathing, not less than 10 mm short way of mesh and not less than 0.4
47、6 mm thick should be used. 5.8 High bond primer A modified synthetic rubber latex emulsion should be applied to provide key to vertical surfaces. 5.9 Sand for rubbing Rubbing sand should be clean sand from natural deposits, predominantly passing a 600mm sieve and retained on a 212mm sieve. 5.10 Ston
48、e chippings (bedded) Stone chippings for use as a protective topping should be washed, crushed rock, normally 10 mm to 14 mm nominal size aggregate, bedded in a proprietary gritting solution over a mastic asphalt membrane. 5.11 Stone aggregate (loose laid) Stone aggregate for use as a protective top
49、ping should be 20 mm nominal size aggregate loose laid over mastic asphalt, but suitably secured around rainwater outlets, internal and external angles, and roof perimeters. 5.12 Ballast Ballast for use on inverted roofs should be clean, rounded aggregate graded 20 mm to 40 mm and as free as practicable from fines, in accordance with the insulation manufacturers recommendations. 5.13 Concrete paving slabs for insulated inverted roof Concrete paving slabs for use as walkways or as paving on terrace decks should conform to BS 7263. 5.14 Concrete paving slab to cold roofs (uninsulate
